add thoughts on ident/string

Author: annevk

cssom/Overview.html

@@ -3901,9 +3901,18 @@ <h4 id=the-csscomponentvalue-interface><span class=secno>5.6.6. </span>The
 
   <pre
    class=idl>[NoInterfaceObject] interface <dfn id=csscomponentvalue>CSSComponentValue</dfn> {
+  readonly attribute DOMString <span title=dom-CSSComponentValue-type>type</span>;
+           attribute any <span title=dom-CSSComponentValue-value>value</span>;
 };</pre>
 
-  <p class=XXX>Components need to identify their current value somehow.
+  <p class=XXX>type returns "string", "ident", "color", "em", "ex", "px",
+   "url".
+
+  <p class=note>&lt;string> and &lt;ident> component values do not have their
+   own interface. They are identified by the <span
+   title=dom-CSSComponentValue-type>type</span> attribute and the <span
+   title=dom-CSSComponentValue-value>value</span> attribute returns a
+   DOMString representing either one of them.
 
   <h4 id=the-csscolorcomponentvalue-interface><span class=secno>5.6.7.
    </span>The <code title="">CSSColorComponentValue</code> Interface</h4>

cssom/Overview.src.html

@@ -2459,10 +2459,17 @@ <h4>The <code title="">CSSPropertyValueList</code> Interface</h4>
   <h4>The <code title="">CSSComponentValue</code> Interface</h4>
 
   <pre class="idl">[NoInterfaceObject] interface <dfn>CSSComponentValue</dfn> {
+  readonly attribute DOMString <span title="dom-CSSComponentValue-type">type</span>;
+           attribute any <span title="dom-CSSComponentValue-value">value</span>;
 };</pre>
 
-  <p class="XXX">Components need to identify their current value
-  somehow.</p>
+  <p class="XXX">type returns "string", "ident", "color", "em", "ex", "px", "url".</p>
+
+  <p class="note">&lt;string> and &lt;ident> component values do not have
+  their own interface. They are identified by the
+  <span title="dom-CSSComponentValue-type">type</span> attribute and the
+  <span title="dom-CSSComponentValue-value">value</span> attribute returns a
+  DOMString representing either one of them.</p>
 
 
   <h4>The <code title="">CSSColorComponentValue</code> Interface</h4>